Gas-burning cigarette lighters



Dec. 17, 1963 v H. LOWENTHAL 3,114,249

GAS-BURNING CIGARETTE LIGHTERS Filed July 28, 1961 I nuenlor #5275 Z awenf/ra/ United States Patent 3,114,249 GAS-BURNING CIGARETTE LIGHTERS Hans Lowenthal, London, England, assignor to Colihri Lighters Limited Filed July 28, 1961, Ser. No. 127,652 Claims priority, application Great Britain Aug. 23, 1960 6 Claims. (Cl. 67-7.1)

This invention relates to cigarette lighters which burn hydrocarbon gas. The gas most commonly used is either butane or propane and to enable a supply of gas to be held in a reservoir which is sufilciently small to be practicable, the gas must be liquefied. At ordinary atmospheric temperatures, the pressure of the liquefied gas is very substantial and, therefore, the gas must pass through a pressure-reducing valve on its passage from the gas reservoir to the burner where it is ignited.

In some gas-burning cigarette lighters, the pressurereducing valve is manually adjustable so that the output pressure of the gas at the burner can be varied to vary the height of the flame. To enable the adjustment to be reasonably sensitive these valves are rather complicated in construction and even then the output pressure may be varied over an excessively wide range. If the valve is fully opened and the cigarette lighter is operated, the resulting flame may be dangerously large,

According to the present invention, a gas-burning cigarette lighter has a gas reservoir with a gas outlet passage leading to a burner and the passage has two pressurereducing valves in series, the valve through which the gas passes first being capable of being set so that the. greater part of the gas pressure reduction between the reservoir and the burner takes place through it, and the other valve being manually adjustable to vary the length of the flame at the burner up to a maximum, which is limited by the setting of the first valve. This arrangement is considerably safer than the earlier arrangement in which the whole pressure reduction takes place through a single valve, which is adjustable, and also the two valves may be very much simpler in construction, and even both together, cheaper than the previous single valve. This is because the first valve, in which the greater part of the pressure reduction takes place, need only be constructed so that it can be permanently set at a certain pressure, that is to say, it need not be readily manually adjustable even though it can be altered to alter the pressure reduction through it. The second valve can also be of a very simple construction since the gas entering it is already at a comparatively low pressure. The pressure drop through the second valve may be only of the order of a few pounds per square inch.

In most gas-burning cigarette lighters there is also a shut-off valve in the burner and this is opened manually when the ignition mechanism of the lighter is operated. The valve may be inter-connected with a fingerpiece which operates the ignition mechanism in such a way that when the fingerpiece is pressed a spark is produced and at the same time the valve is opened. This shut-off valve is usually spring-loaded.

The first pressure-reducing valve may be temperature compensated. That is to say, when the temperature of the valve and thus also the temperature and the corresponding pressure of the gas in the reservoir increases, the passage through the valve is automatically restricted so that the pressure on the outlet side of the valve remains substantially constant or at least undergoes a smaller variation than the pressure within the reservoir. Particularly when the first pressure-reducing valve is temperature compensated in this way there are advantages in causing the gas to flow directly from the first valve to the second valve without any intervening space between them in which the gas pressure may build up.

3,114,249 Patented Dec. 17, 1963 To achieve this, the second pressure-reducing valve is situated immediately adjacent the first valve and a part of the first valve forms a valve seat for the second valve. The second valve is preferably some form of screw-down valve which has a tapering valve closure member. The closure member tapers in such a way that as the valve is opened the area of the opening increases gradually as the valve is opened further. The valve member may, for example, be conical, but in some cases, a part-spherical surface is satisfactory.

In most lighters the burner is fixed directly to the gas reservoir and may be removed from the lighter with the reservoir. In this case both of the pressure-reduction valves are built into the lighter reservoir structure itself. In some cases, however, particularly those in which the gas reservoir, when empty, is intended to be thrown away and replaced with a new full reservoir, the first pressurereducing valve may be permanently fixed to the reservoir, but the second valve may then form a part of the lighter casing in which the reservoir is fitted. In this latter case a seal must be formed between the reservoir and the lighter casing to prevent leakage of gas between the two valves. This is not, however, difiicult because the gas is at a cornparatively low pressure after passing through the first pressure-reducing valve.

One example or" part of a lighter constructed in accordance with the present invention is illustrated in the accompanying drawing which is a vertical section through a valve assembly fixed in the wall of a lighter reservoir.

The assembly has an outer cup shaped body 101, which is made of brass, and which has at its upper end a small radially projecting flange 114. The assembly is intended to be fitted in an opening in the wall of a lighter which fits closely around the outer body 101 and to which the flange 114 is brazed. In the bottom of the body 101 is a resilient block 102 having a central bore 103 and being held in place by a hollow tubular screw-threaded plug 104. Gaseous fuel from the lighter reservoir enters the assembly through a hole 115 in the body of the body'101 and passes upwardly through the bore 103. The resilient block 102 forms the first pressure reducing valve in the assembly. Its central bore 105 can be opened or closed by releasing or compressing the block 102 by screwing out or in respectively the hollow plug 104.

The second pressure reducing valve is immediately adjacent the first valve formed by the restricted bore 103. The second valve is formed by a spherical rubber ball 105 which seats on the outlet end of the bore 103 and also on the inlet end of a bore 106 formed in an inner sleeve 107 which is screwed into the plug 104. The space between the plug 104 and the sleeve 107 is sealed by an easily compressible rubber O-ring 108 which lies between the lower ends of the sleeve and the plug. In order to pass from the bore 103 to the bore 106 the gas must compress the ball 105 so that it can both escape from the upper end of the bore 103 and also enter the lower end of the bore 106. In passing through the gap between the ball and the parts surrounding these two bores, the pressure of the gas is further reduced and the amount of reduction depends upon the compression of the ball 10S and this in turn can be adjusted by rotating the sleeve 107 by means of a knurled flange 109 at its upper end. On the inside of the sleeve 107 surrounding the outlet end of the bore 106 is a valve seat 110 which is closed by a closure member 111. The closure member is held on its seat by a spring 112 and has a hollow tubular stem 113.

The closure member 111 forms a shut-off valve which can be opened against the action of the spring 112 by lifting the tubular stem 113 by an opening mechanism which is not shown. When the closure member 111 is lifted, gas from inside the reservoir, which has flowed through the bore 103 passes around the ball 105, through '7 a the bore 106, around the lower end of the closure member 111 and of the hollow stem 113 into the bore of the hollow stem 113 through ports 116 and out through the burner nozzle 117 where it is i nited by an igniting mechanism of the lighter.

The main pressure reduction through the whole valve assembly takes place through the bore 103 and only a substantially smaller part of the reduction takes place around the ball 105. As has already been explained, the pressure reduction through the bore 103 can be adjusted by turning the screw threaded plug 104 within the body 101, but this adjustment is usually permanently set when the lighter is manufactured and the plug 1(14 may then be sealed in position in the housing 101. Fine adjustments of the height of the flame made by rotating the knurled flange 109 as required.

The resilient block 102 which forms the first pressure reduction valve may be made of polytetrafiuoroethylene which has a very high coefficient of expansion. When the surrounding housing is made of brass, which has a lower coefficient of expansion, there is a substantial differential expansion between the block and the surrounding housing. Since the block expands more as the temperature rises its compression is increased and therefore as the temperature rises the bore 103 in the block is automatically further restricted. The pressure Within the gas reservoir is dependent upon this temperature and therefore the valve closes as the pressure upon it increases. In this way the pressure on the outlet side of the bore 103 is prevented from varying to such a great extent as the pressure within the tank. In fact the valve may be designed so that the outlet pressure remains substantially constant. The height of the flame when the gas burns at the nozzle 117 is then only dependent upon the manual adjustment to the knurled flange 109.

I claim:

1. In a gas-burning cigarette lighter comprising a gas reservoir, a burner, and a gas outlet passage leading from said gas reservoir to said burner, the improvement which comprises first and second pressure-reducing valves immediately adjacent each other in series in said gas outlet passage, a part of said first valve forming a valve seat for said second valve, said first valve being adjustable to a position in which the greater part of the gas pressure reduction between said reservoir and said burner taltes place therethrough so as to limit the length of the flame at the burner to a desired maximum, and manually adjustable means for controlling said second valve and thereby varying the length of the flame at the burner up to the maximum permitted by the position of said first valve.

2. A lighter according to claim 1 in which the first pressure-reduction valve is temperature compensated.

3. A lighter according to claim 1 in which the first pressure-reducing valve comprises a block of resilient material which has a gas passage through it and means for compressing said block to restrict the passage, thus altering the area of the passage and the pressure drop through the valve.

4. A lighter as claimed in claim 3 in which said block of resilient material has a high coefiieient of expansion and is retained within a casing having a lower coefficient of expansion so that an increase in temperature causes expansion of the material of said resilient block into the gas passage therein, thus restricting said passage.

5. A lighter according to claim 3 in which the second pressure-reducing valve comprises a resilient valve closure member which seats on the outlet end of the passage through the resilient block, the closure member being held on its seat by an adjustable member, adjustment of which varies the pressure required to distort the closure member and allow gas to flow through the passage and thus also varies the pressure drop through the second valve.

6. A lighter according to claim 5 in which the resilient closure member is a ball which seats around the passage through the resilient block and also around a diametrically opposite passage through a housing in which it is held.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A GAS-BURNING CIGARETTE LIGHTER COMPRISING A GAS RESERVOIR, A BURNER, AND A GAS OUTLET PASSAGE LEADING FROM SAID GAS RESERVOIR TO SAID BURNER, THE IMPROVEMENT WHICH COMPRISES FIRST AND SECOND PRESSURE-REDUCING VALVES IMMEDIATELY ADJACENT EACH OTHER IN SERIES IN SAID GAS OUTLET PASSAGE, A PART OF SAID FIRST VALVE FORMING A VALVE SEAT FOR SAID SECOND VALVE, SAID FIRST VALVE BEING ADJUSTABLE TO A POSITION IN WHICH THE GREATER PART OF THE GAS PRESSURE REDUCTION BETWEEN SAID RESERVOIR AND SAID BURNER TAKES PLACE THERETHROUGH SO AS TO LIMIT THE LENGTH OF THE FLAME AT THE BURNER TO A DESIRED MAXIMUM, AND MANUALLY ADJUSTABLE MEANS FOR CONTROLLING SAID SECOND VALVE AND THEREBY VARYING THE LENGTH OF THE FLAME AT THE BURNER UP TO THE MAXIMUM PERMITTED BY THE POSITION OF SAID FIRST VALVE. 